Effects Of Enriched Environment On Spatial Memory And Expression Of Beclin-1 And LC3 In Hippocampus Of HIBD Rats

Objective:To observe the effects of riched environment intervention on spatial memory ability and expression of Beclin-1 and LC3 protein in hippocampus of neonatal rats with HIBD,and to explore the relevant mechanisms of enriched environmental treatment for HIBD,so as to provide theoretical basis for clinical application.Method:Ten Sprague-Dawley germline pregnant females were selected for spontaneous delivery and 72 rats of 7-day-old were selected.They were randomly divided into sham operation group,model group,and enriched environment(EE)group.Each group was divided into 14 days,28days subgroups(n=12).Rats in the model group and environment-enhanced group were used to establish a HIBD animal model using the modified Rice method.Rats in the EE group were given plenty of environmental stimuli daily.Morris water maze test was performed at the 9th and 23rd days after modeling.At the 14th and 28th days after modeling,the damage of neurons in hippocampus of rats in each group was observed by Nissl staining.The protein expression of Beclin-1 and LC3 in hippocampus was detected by Western blotting.Result:1.Spatial learning and memory ability of rats in each groupMorris water maze:At 9d and 23d after model establishment,positioning navigation capability was started and rats were trained for 5 days.On the day of completion of positioning and navigation capability testing,space exploration capabilities were tested.The statistical analysis was performed on the mean escape latency and the staying time of the original platform quadrant of the rats at 14d and 28d after modeling.Compared with the sham operation group,the mean escape latency was prolonged in the model group and the stay in the original platform quadrant was decreased on the 14th and 28th days after modeling(P<0.05).Compared with the model group,the average escape avoidance period of the EE group was shortened on the 14th day after modeling,and the stay time of the original platform quadrant was increased,but the difference was not statistically significant(P>0.05).The average escape avoidance period of the EE group on the 28th day after modeling was shortened,and the stay time of the original platform quadrant was increased,the difference was statistically significant(P<0.05).2.Neuronal damage in hippocampus of rats in each groupNissl staining:Compared with the sham operation group,various degrees of neuronal degeneration,necrosis,disintegration,nuclear condensation,and fragmentation were observed,and part of the cell's structural integrity was lost in the hippocampus of rats in the model group on the 14th and 28th days after modeling.Compared with the model group,the pathological injury of the EE group was lighter than that of the model group on the 14th day after modeling,and the pathological injury of the EE group was significantly less than that of the model group on the 28th day after modeling.3.Beclin-1 and LC3 protein expression in hippocampus of rats in each groupWestern Blotting:Compared with the sham operation group,the expression of Beclin-1 and LC3 protein in the hippocampus of rats in the model group was increased on the 14th and 28th days after modeling(P<0.05).Compared with the model group,the expression levels of Beclin-1 and LC3 protein in the hippocampus of rats in the EE group at the 14th day after modeling were decreased,but the difference was not statistically significant(P>0.05).The Beclin-1 and LC3 in the hippocampus of rats at 28 days after modeling were performed.The level of protein expression was decreased,and the difference was statistically significant(P<0.05).Conclusions:1.Enrichment of environmental stimuli can effectively improve the neuronal damage in hippocampus of HIBD rats,and promote the recovery of learning and memory ability and spatial orientation ability;2.Enriched environmental stimuli can down-regulate the expression of Beclin-1 and LC3 proteins in hippocampus of HIBD rats,inhibit autophagy and improve neuronal damage.